Wounds that heal by second intention are ones that require connective tissue growth to fill in dead space, such as occurs with a stage IV pressure ulcer with tunneling and epibole. A classical cesarean section incision is an example of a wound that heals by primary intention, which occurs when the wound is sutured closed. An abdominal wound caused by impalement on a wooden fence post would be healed by third intention because debris is likely embedded in the wound, requiring irrigation and removal of the debris. Additionally, there is likely significant inflammation to the underlying tissues which would hinder wound healing if the wound is sutured closed prematurely. Therefore, the wound is left open for a few days until the inflammation subsides and the wound is properly cleaned; then the wound is stitched closed. Road rash is not an open wound; the gravel and glass embedded in the wound may leave open wounds that require sutures, but they would be less likely to require the growth of connective tissue to close the wound.